Medical Device Having Laminate-Coated Braid Assembly

ABSTRACT

A catheter includes a braid assembly having a dual-laminate coating. The braid assembly includes a plurality of braid members interwoven to provide for interstices between the braid members, each braid member having an electrically conductive element, a flexible non-electrically-conductive polymer coating that insulates the electrically conductive element and a thermoplastic bonding adhesive coating. The braid assembly is formed between an inner polymer layer and an outer polymer layer. One or more of the braid members may be coupled to an energy delivery element.

The application is a continuation of U.S. application Ser. No.14/723,068, filed 27 May 2015, now pending, which is a continuation ofU.S. application Ser. No. 14/486,456, filed 15 Sep. 2014, now U.S. Pat.No. 9,060,785, which is a division of U.S. patent application Ser. No.12/392,821, filed 25 Feb. 2009, now U.S. Pat. No. 8,864,744. Each of theforgoing is hereby incorporated by reference as though fully set forthherein.

BACKGROUND OF THE INVENTION a. Field of the Invention

The present invention pertains generally to electrophysiological devicesand methods for diagnosing and treating biological tissue and, moreparticularly, to diagnostic and therapeutic catheters having alaminate-coated braid assembly.

b. Background Art

Catheters are used for an ever-growing number of procedures. Forexample, catheters are used for diagnostic, therapeutic, and ablativeprocedures, to name just a few examples. Typically, the catheter ismanipulated through a patient's vasculature and to the intended site,for example, a site within the patient's heart. The catheter typicallycarries one or more electrodes, which may be used for ablation,diagnosis, or the like.

Since the path through the patient's vasculature to the intended site isoften long and tortuous, steering forces typically must be transmittedover relatively great distances. Accordingly, it is desirable for acatheter to have sufficient flexibility to substantially conform to thepatient's vasculature and yet resist kinking as it does so. Kinking isoften the result of a localized failure of the material of the catheterwhen localized stresses exceed the yield strength of the material. Toprovide flexibility and kink resistance, many extant catheters includemetallic wire braiding.

Many catheters also include one or more electrical wires for energizingelectrodes or other energy delivery or diagnostic elements. Theelectrical wires must be insulated from the wire braiding, if present,and other internal components in order to prevent electrical shorts. Insome cases, the braid wires may serve as the electrical wires. In orderfor braid wires to be implemented as the electrical wires, the braidwires must be insulated, otherwise contact between adjacent braid wiresmay induce electrical shorts. Most existing insulative coatings are toostiff for use in steerable devices and tend to result in tears thatcause electrical shorts after only a few articulations of the device,for example as few as 10-12 articulations. What is needed, therefore,are flexible braid assemblies having insulated braid members that canwithstand a greater number of articulations without tearing.

BRIEF SUMMARY OF THE INVENTION

The present invention provides for catheters having improved braid wireassemblies.

An object of the present invention is to provide catheters having braidwire assemblies that can be used to conduct electrical energy to one ormore energy delivery elements.

Another object of the present invention is to provide braid wireassemblies having improved coatings that impart both insulatingproperties and flexibility.

A further object of the present invention is to provide medical devicesincorporating braid wire assemblies having insulative coatings withimproved durability.

In one embodiment, a catheter shaft of the present invention includes aninner layer of a first polymeric material, an outer layer of a secondpolymeric material, and a braid assembly formed between the inner layerand the outer layer. The braid assembly includes a plurality of braidmembers interwoven to provide for interstices between the braid members,and each of the plurality of braid members includes an electricallyconductive element having a first coating and a second coating. Thefirst coating is made of a flexible non-electrically-conductive polymerthat insulates the electrically conductive element, and the secondcoating is made of a thermoplastic bonding adhesive that bonds to theouter layer. The first coating may be a polyurethane material and mayhave a durometer in the range of Shore A-50 to Shore A-70. In one form,the first coating is selected for its flexibility to withstand more than50 articulations. In another form, the first coating is selected for itsflexibility to withstand more than 150 articulations. The second coatingmay be a polyamide material and may have a durometer in the range ofShore D-40 to Shore D-50.

The electrically conductive element may include a copper alloy or platedcopper and/or at least one of steel, stainless steel, beryllium, nickel,cobalt, zinc, aluminum, tantalum, platinum, iridium, gold, and silver.In one aspect, the electrically conductive element includes about 0.5%to about 5% beryllium. In another aspect, the electrically conductiveelement is a flat wire. In a further aspect, the flat wire has roundededges.

The catheter shaft may further include at least one energy deliveryelement disposed along a distal end of the shaft. In one aspect, theenergy delivery element is a radiofrequency electrode, an ultrasoundtransducer, or a microwave element. Each energy delivery element may becoupled to one braid member. For example, a first of the plurality ofbraid members may be electrically coupled to a first of the energydelivery elements, and a second of the plurality of braid members may beelectrically coupled to a second of the energy delivery elements. Thecatheter shaft may include 2-16 energy delivery elements.

In another embodiment, a catheter of the present invention includes anelongate catheter body having an outer surface, a proximal end, a distalend, and an inner lumen extending between the proximal and distal ends.One or more energy delivery elements are disposed along the distal endof the elongate catheter body. The catheter also includes a braidassembly extending from at or near the proximal end to at or near thedistal end. The braid assembly includes a plurality of braid membersinterwoven to provide for interstices between the braid members, andeach of the plurality of braid members includes an electricallyconductive element having a first coating and a second coating. Thefirst coating is made of a flexible non-electrically-conductive polymerthat insulates the electrically conductive element, and the secondcoating is made of a heat sensitive bonding adhesive. At least one ofthe plurality of braid members is electrically coupled to each of theone or more energy delivery elements. In one aspect, the braid assemblyis formed between an inner polymer layer and an outer polymer layer.

The electrically conductive element may include a copper alloy or platedcopper and/or at least one of steel, stainless steel, beryllium, nickel,cobalt, zinc, aluminum, tantalum, platinum, iridium, gold, and silver.In one aspect, the electrically conductive element includes about 0.5%to about 5% beryllium. In another aspect, the electrically conductiveelement is a flat wire. In a further aspect, the flat wire has roundededges.

The first coating may include a polyurethane material, and the secondcoating may include a polyamide material. In one aspect, the firstcoating is selected for its flexibility to withstand more than 50articulations. In another aspect, the first coating is selected for itsflexibility to withstand more than 150 articulations. The one or moreenergy delivery elements may be one of a radiofrequency electrode, anultrasound transducer, and a microwave element. The catheter may includefrom 2-16 energy delivery elements.

A method of manufacturing a catheter includes the steps of forming aninner layer of a first polymer, forming a braided assembly layer aboutthe inner layer, and forming an outer layer of a second polymer aboutthe braided assembly layer. The braided assembly layer includes aplurality of braid members interwoven to provide for interstices betweenthe braid members, and the step of forming the braided assembly layerincludes providing a plurality of electrically conductive elements,coating the electrically conductive elements with a first coating, thefirst coating comprising a flexible non-electrically-conductive polymerthat insulates the electrically conductive element, coating theelectrically conductive elements with a second coating, the secondcoating comprising a heat sensitive bonding adhesive, and braiding theelectrically conductive elements to form a braided assembly layer.

In one aspect, the method further includes heating the inner layer, thebraided assembly layer and the outer layer to bond the inner layer, thebraided assembly layer and the outer layer together. In another aspect,the method further includes introducing a heat-shrink tube about theouter layer prior to the heating step. The step of forming the innerlayer may include extruding the inner layer about a core rod, and thestep of forming the braided assembly layer about the inner layer mayinclude braiding the braid members about the inner layer. Also, the stepof forming the outer layer about the braided assembly layer may includeextruding the outer layer about the braided assembly layer. The methodmay further include the step of forming at least one energy deliveryelement about a distal end of the outer layer and electrically couplingat least one of the braid members to the at least one energy deliveryelement.

An advantage of the present invention is that the braid wire assembliescan serve as the conductive element for one or more energy deliveryelements, thus reducing the thickness of the catheter and increasing theusable inner diameter of the catheter.

Another advantage is that catheters made according to the presentinvention are sufficiently flexible to withstand a greater number ofarticulations without causing tears that lead to electrical shorts.

The foregoing and other aspects, features, details, utilities, andadvantages of the present invention will be apparent from reading thefollowing description and claims, and from reviewing the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an exemplary catheter according to anembodiment of the present invention.

FIG. 2 is an axial cross-sectional view of a braid member according toan embodiment of the invention.

FIG. 3 is a longitudinal cross-sectional view of a braid memberaccording to an embodiment of the invention.

FIG. 4 depicts an axial cross-sectional view of the various componentsof a catheter shaft assembly according to an embodiment of the presentinvention prior to the application of heat to melt process the cathetershaft assembly.

FIG. 5 is a longitudinal cross-sectional view of the various componentsof a catheter shaft assembly according to an embodiment of the presentinvention prior to the application of heat to melt process the cathetershaft assembly.

FIG. 6 is an axial cross-sectional view of a catheter shaft assemblyaccording to an embodiment of the invention during the application ofheat to melt process the catheter shaft assembly.

FIG. 7 is an axial cross-sectional view of a catheter shaft according toan embodiment of the invention after the application of heat to meltprocess the catheter shaft assembly.

FIG. 8 illustrates a perspective view of a partially assembled catheterin accordance with an embodiment of the invention, cut away to showdetails.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a catheter shaft suitable for use in thehuman vasculature for known medical procedures, such as cardiac mappingand ablation. For purposes of this description, the invention will bedescribed in connection with an elongate electrophysiology catheter. Itis contemplated, however, that the described features and methods may beincorporated into any number of devices (e.g., steerable catheters,introducers, sheaths, and the like) as would be appreciated by one ofordinary skill in the art.

Referring now to FIG. 1, an electrophysiology catheter 10 includes ashaft 12 having a distal end 14 and a proximal end 16. A handle 18 maybe coupled to the proximal end 16 of the shaft 12 to control thecatheter 10 (e.g., to push and/or torque the catheter 10). The catheter10 may also include a hub 20 operably coupled to an inner lumen (notshown) within the handle 18. A valve 22 may be operably connected to thehub 20. Of course, it is also contemplated that any known device formanipulation of the catheter 10 may be coupled to the proximal end 16,including, without limitation, robotic manipulation devices and thelike.

As shown in FIG. 8, in one aspect, the catheter shaft includes an innerlayer 26, a braid assembly 28, and an outer layer 30. The braid assembly28 includes multiple braid members 46. Catheter shafts according to thepresent invention advantageously utilize improved braid assemblieshaving insulated braid members that are sufficiently flexible towithstand multiple catheter articulations without inducing tears in theinsulative coating of the braid members. The braid assemblies of thepresent invention employ a dual-laminate coating over the braid members.A benefit of the described braid assemblies is that the braid memberscan serve as conductive elements for energizing electrodes or otherenergy-delivery elements present within the device. Even if not servingas conductive elements, the insulative coating on the braid membersadvantageously insulates the braid wires from other internal componentswithin the catheter or device, thus reducing or eliminating the need forinsulative layers elsewhere in the device, while at the same timemaintaining a high degree of flexibility. The braid assemblies of thepresent invention also serve to reduce the overall thickness of thedevice and increase the usable space within the device.

As illustrated in FIGS. 2 and 3, the braid members 46 include aconductive element 40, a first coating 42 and a second coating 44. Inone aspect, the conductive element 40 is an electrically conductivemetallic material, such as a conductive wire, alloy or clad material.The conductive element 40 may include, for example, one or more of gold,silver, platinum, iridium, titanium, tantalum, zirconium, vanadium,niobium, hafnium, aluminum, silicone, tin, chromium, molybdenum,tungsten, lead, manganese, beryllium, iron, cobalt, nickel, palladium,osmium, rhenium, technetium, rhodium, ruthenium, cadmium, copper, zinc,germanium, arsenic, antimony, bismuth, boron, scandium and metals of thelanthanide and actinide series. In another aspect, the material used tomanufacture the conductive element is a bio-compatible electricallyconductive material, but other electrically conductive materials coatedwith bio-compatible materials may also be employed, including, forexample, gold-plated copper. In another aspect, the conductive element40 comprises a conductive fibrous material, for example, conductiveKevlar.

The conductive element 40 may be selected for its conductive propertiesas well as its strength and flexibility. In one aspect, the conductiveelement 40 is a copper alloy, or plated copper. For example, theconductive element 40 may be a copper alloy preferably having about 90%to about 99.5% copper and about 0.5% to about 10% beryllium, morepreferably about 98% copper and about 2% beryllium. The conductiveelement 40 preferably has a tensile strength of about 150 to about 200kpsi, more preferably about 170 kpsi.

In a further aspect, the conductive element 40 may be copper clad steel,for example, copper clad steel wherein the copper is about 99.5% purecopper and the steel is 1010 steel. In this aspect, the copper cladsteel preferably has a volume of about 20% to about 60% copper and about40% to about 80% steel, more preferably about 40% copper and about 60%steel and has an ultimate tensile strength of about 125 kpsi.

In another aspect, the conductive element 40 may be a flat wire or around wire. For example, the conductive element 40 may be a flat wirehaving dimensions of about 0.0015″ to about 0.005″ by about 0.002″ toabout 0.020″. For example, the conductive element 40 may have dimensionsof about 0.001″×0.005″, 0.002″×0.006″, 0.003″×0.007″, or 0.0015″×0.008″.These dimensions are merely exemplary as a person of skill in the artwill be able to select an appropriately sized conductive element forparticular applications. After application of the dual laminate coating(i.e., the first coating 42 and the second coating 44), the overalldimensions of the conductive element 40 increase by about 0.00025″ toabout 0.00100″ in each direction. In another aspect, the flat wire mayhave rounded edges. A flat wire with rounded edges is advantageousbecause the rounded or “soft” edges reduce the risk of tearing. In afurther aspect, the conductive element 40 is a round wire having adiameter of about 0.0005″ to about 0.005″.

The first coating 42 is a flexible, non-electrically-conductive polymerthat insulates the wire 40. The first coating 42 is selected for itsflexibility. In other words, the first coating 42 is a flexible coatingthat moves with the braid assembly during catheter articulation andminimizes friction between the conductive element 40 and the firstcoating 42 during articulation. The first coating 42 is also selectedfor its dielectric properties to insulate the conductive element 40 fromother braid members and from other internal components within thedevice. In one aspect, the first coating is a polyurethane material. Thepolyurethane material may have a durometer in the range of about Shore A50-70, and a melt temperature of about 350° F. to about 400° F. Inanother aspect, the first coating 42 is a polyimide material having amelt temperature of about 450° F. to about 500° F.

The second coating 44 is a thermoplastic bonding adhesive. The secondcoating 44 increases the bonding of the braid assembly 28 to an outerpolymer layer 30, described in more detail below, and thus decreases thefriction between the braid assembly 28 and the outer layer 30. Thisresults in a catheter assembly that can withstand a substantially largernumber of articulations without causing tears in the first and secondcoatings. In one aspect, the second coating comprises a thermoplasticpolyamide. The thermoplastic polyamide may have a durometer in the rangeof about Shore D 40-50. The second coating 44 has a melt temperature ofabout 300° F. to about 350° F. One example of a suitable material forthe second coating 44 is Kanthal™ Bond M-A.

The first coating 42 and the second coating 44 may be applied to theconductive element 40 in a number of ways, for example using a roller orspray process. In one aspect, the coatings are applied using atwo-dimensional (i.e., horizontal and vertical) coating process toachieve a more uniform application, especially at or near the edges ofthe conductive element. The dual laminate coating comprising the firstcoating 42 and the second coating 44 is advantageous in severalrespects. For example, the combination of the first coating 42 and thesecond coating 44 provide unique mechanical properties to aid withspring-back during catheter articulation. In addition, braid assembliesincorporating the dual laminate coating comprising the first coating 42and the second coating 44 have fewer tears after multiple articulations.Previous insulating coatings resulted in tears after as few as 10-12catheter articulations. Catheter assemblies utilizing braid assembliesof the present invention, however, can withstand at least 100articulations, and preferably up to 200 articulations, without tearing.

The dual laminate coating of the present invention is also advantageousin that it allows the braid wire assembly to bond to an outer catheterlayer to create a significant increased substrate structure between thebraid assembly and the outer layer. The improved bonding of the braidassembly to the outer layer increases the effectiveness of catheterarticulation.

A basic method of manufacturing the catheter 10, and in particular of atleast a portion of the shaft 12, according to an embodiment of thepresent invention will be described with reference to FIGS. 4-7. As theyare assembled, the catheter components will be collectively referred toas a “catheter shaft assembly.”

As depicted in FIG. 4, a mandrel 24, such as a hardened stainless steelmandrel or a core rod, is provided. The mandrel or core rod 24 may beround in cross-section and from about 6 inches to about 4 feet inlength. The mandrel or core rod 24 has a distal end and a proximal end.An inner layer 26 is formed about the mandrel or core rod 24. In oneembodiment, the inner layer 26 may be formed by extruding a polymermaterial about the mandrel or core rod 24. In another embodiment, theinner layer 26 may be separately extruded and then slipped about themandrel or core rod 24.

The inner layer 26 may be an extruded polymeric tubing, such aspre-extruded (and optionally chemically-etched) polytetrafluoroethylene(PTFE) tubing (e.g., Teflon® brand tubing). Inner layer 26 may also bemade of other melt-processable polymers, including, without limitation,fluorinated ethylene-propylene copolymer (FEP), perfluoroalkoxyethylene(PFA), poly(vinylidene fluoride), poly(ethylene-co-tetrafluoroethylene),nylon (for example Nylon 911) and other fluoropolymers with surfacetreatment such as chemical etching, plasma and corona treatment, and thelike. For example, the inner layer 26 may be made of Pebax®, a polyetherblock amide made by Arkema, Inc. Pebax® of various durometers may beused, including, without limitation, Pebax 55D to Pebax 72D. Liquidcrystal polymers (LCPs) are also suitable materials for the inner layer26.

A braid assembly 28 may then be formed about inner layer 26. The braidassembly 28 includes multiple braid members 46 (see FIGS. 2-3) formed ina braid pattern. As discussed above with reference to FIGS. 2-3, thebraid members 46 include a conductive element 40, a first coating 42 anda second coating 44. The braid assembly 28 may be formed in a standardbraid pattern and density, for example, about 16 wires at about 45 toabout 60 picks per inch (“PPP”) density. Alternatively, a braid assemblymay be used that is characterized by a varying braid density. Forexample, the braid assembly 28 may be characterized by a first braiddensity at proximal end 16 of the catheter shaft 12 and then transitionto one or more different braid densities as the braid assembly 28approaches distal end 14 of the catheter shaft 12.

The braid assembly 28 may be formed separately on a disposable core andslipped about the inner layer 26. Alternatively, the braid assembly 28may be braided directly upon the inner layer 26. In addition, one ormore portions of the braid assembly 28 may be heat tempered and cooledbefore incorporation into the catheter shaft assembly through methodsthat are known to those of ordinary skill in the art. The action of heattempering may help to release the stress on the conductive element 40and help reduce radial forces.

An outer layer 30 may be formed about the braid assembly 28. The outerlayer 30 may be formed by extruding a polymer material about the braidassembly 28. In some embodiments of the invention, the outer layer 30may be separately extruded and then slipped about the braid assembly 28,such as illustrated in FIG. 4.

The outer layer 30 is typically a melt-processable polymeric tube, suchas an extruded polytetrafluoroethylene (PTFE) tubing (e.g., Teflon®brand tubing), optionally with surface chemical etching. One of ordinaryskill will appreciate that the outer layer 30 may also be made of othermelt-processable fluoropolymers, including, without limitation,fluorinated ethylene-propylene copolymer (FEP), perfluoroalkoxyethylene(PFA), poly(vinylidene fluoride), poly(ethylene-co-tetrafluoroethylene),and the like with surface treatment. The outer layer 30 may also be madeof melt processable thermoplastic elastomers with sufficiently highmechanical strength and rigidity, including, without limitation, nylon(for example, Nylon 911), polyamide-based thermoplastic elastomers(namely poly(ether-block-amide), polyester-based thermoplasticelastomers (e.g., Hytrel®), thermoplastic polyurethanes (e.g.,Pellethane®, Estane®), and the like, and any combinations thereof. Forexample, the outer layer 30 may be made of Pebax®, a polyether blockamide made by Arkema, Inc. Pebax® of various durometers may be used,including, without limitation, Pebax 55D to Pebax 72D. Liquid crystalpolymers (LCPs) are also suitable materials for the outer layer 30.

FIG. 4 displays an axial-cross section of the catheter shaft assemblyincluding mandrel 24, inner layer 26, braid assembly 28, and outer layer30 before thermal lamination of the various layers by heating (e.g.,reflow bonding). FIG. 5 depicts a longitudinal cross-section of thecatheter shaft assembly at the same stage of manufacture. As shown inFIG. 6, the catheter shaft assembly may then be melt-processed. In someembodiments of the invention, a heat shrink tube 32 is placed over outerlayer 30. The heat shrink tube 32 is preferably a fluoropolymer such asfluorinated ethylene-propylene copolymer (FEP). As an alternative tousing a heat shrink tube 32, the catheter shaft assembly may be placedinto a suitable mold prior to subsequent processing. Either the heatshrink tube 32 or a suitable mold may be generally referred to as a“shape retention structure,” so named because it retains the overallshape of the catheter shaft assembly (that is, the generally circularaxial cross-section) during melt-processing.

Energy (e.g., radiofrequency energy or thermal energy) is applied to thecatheter shaft assembly, for example to the outer surface of thecatheter shaft assembly, to bond inner layer 26, braid assembly 28 andouter layer 30 together in a process often referred to as “reflowbonding.” The second coating 44 on the braid members 46 will bond to theouter layer 30. The heat shrink tube 32 has a higher melting orsoftening temperature than inner layer 26, second coating 44, and outerlayer 30, such that, during the melting process, the heat shrink tube 32will maintain its tubular shape and/or contract during the reflowprocess. The combination of applied energy and pressure exerted by theheat shrink tube 32 forces inner layer 26, second coating 44 on thebraid assembly 28, and outer layer 30 to flow locally and redistributeabout the circumference of the catheter shaft assembly and melttogether.

Once the catheter shaft assembly has cooled, mandrel 24 can be removed,leaving a central lumen 38 (FIG. 7) extending through at least a portionof catheter shaft 12. Optionally, heat shrink tube 32 may also beremoved, such that outer layer 30 becomes the outermost layer of thecatheter shaft assembly. FIG. 7 depicts the catheter shaft assemblyafter the conclusion of the reflow bonding process (that is, FIG. 7depicts an axial-cross section of a catheter shaft formed according toan embodiment of the present invention).

In one aspect, devices of the present invention include one or moreenergy delivery elements (not shown). Each energy delivery element maybe coupled to at least one braid member, for example, using an epoxy.The energy delivery element may be a radiofrequency electrode, anultrasound transducer or a microwave element. The devices of theinvention may include a single energy delivery element, up to fourenergy delivery elements, up to eight energy elements, up to sixteenenergy delivery elements, or more than sixteen energy delivery elements.As a person of skill in the art will appreciate, the braid pattern canbe selected to accommodate various numbers of energy delivery elements.

Although multiple embodiments of this invention have been describedabove with a certain degree of particularity, those skilled in the artcould make numerous alterations to the disclosed embodiments withoutdeparting from the spirit or scope of this invention. For example, thecatheter assembly may include additional polymer layers in addition tothe inner layer and outer layer. Further, helical windings may be usedin place of the braid assembly.

All directional references (e.g., upper, lower, upward, downward, left,right, leftward, rightward, top, bottom, above, below, vertical,horizontal, clockwise, and counterclockwise) are only used foridentification purposes to aid the reader's understanding of the presentinvention, and do not create limitations, particularly as to theposition, orientation, or use of the invention. Joinder references(e.g., attached, coupled, connected, and the like) are to be construedbroadly and may include intermediate members between a connection ofelements and relative movement between elements. As such, joinderreferences do not necessarily infer that two elements are directlyconnected and in fixed relation to each other. It is intended that allmatter contained in the above description or shown in the accompanyingdrawings shall be interpreted as illustrative only and not limiting.Changes in detail or structure may be made without departing from thespirit of the invention as defined in the appended claims.

1. A catheter comprising: an elongate catheter body having an outersurface, a proximal end, a distal end, and an inner lumen extendingbetween the proximal and distal ends; an energy element disposed alongthe distal end of the elongate catheter body; and a braid assemblyextending from the proximal end to the distal end, wherein the braidassembly is formed between an inner polymer layer and an outer polymerlayer, the braid assembly comprising a plurality of braid membersinterwoven to provide for interstices between the braid members, whereinthe density of the braid at the proximal end is different from thedensity of the braid at the distal end, and wherein at least one of theplurality of braid members comprises an electrically conductive elementcomprising a flexible dual-laminate coating comprising an inner layerand an outer layer, wherein the outer layer of the dual-laminate coatinghas a durometer of Shore D of about 40-50, and wherein the electricallyconductive element is electrically coupled to the energy element. 2.(canceled)
 3. The catheter according to claim 1, wherein theelectrically conductive element comprises a copper alloy or platedcopper.
 4. The catheter according to claim 3, wherein the electricallyconductive element comprises at least one of steel, stainless steel,beryllium, nickel, cobalt, zinc, aluminum, tantalum, platinum, iridium,gold, and silver.
 5. The catheter according to claim 3, wherein theelectrically conductive element further comprises about 0.5% to about 5%beryllium.
 6. The catheter according to claim 1, wherein theelectrically conductive element is a flat wire. 7-12. (canceled)
 13. Amethod of manufacturing a catheter, comprising the steps of: forming aninner layer of a first polymer; forming a braided assembly layer aboutthe inner layer; and forming an outer layer of a second polymer aboutthe braided assembly layer, wherein the braided assembly layer comprisesa plurality of braid members interwoven to provide for intersticesbetween the braid members and wherein the step of forming the braidedassembly layer comprises providing a plurality of electricallyconductive elements; coating the electrically conductive elements with afirst coating, the first coating comprising a flexiblenon-electrically-conductive polymer that insulates the electricallyconductive element; coating the electrically conductive elements with asecond coating, the second coating comprising a heat sensitive bondingadhesive; and braiding the electrically conductive elements to form abraided assembly layer.
 14. The method according to claim 13, furthercomprising heating the inner layer, the braided assembly layer and theouter layer to bond the inner layer, the braided assembly layer and theouter layer together.
 15. The method according to claim 14, furthercomprising introducing a heat-shrink tube about the outer layer prior tothe heating step.
 16. The method according to claim 13, wherein the stepof forming the inner layer comprises extruding the inner layer about acore rod.
 17. The method according to claim 13, wherein the step offorming the braided assembly layer about the inner layer comprisesbraiding the braid members about the inner layer.
 18. The methodaccording to claim 13, wherein the step of forming the outer layer aboutthe braided assembly layer comprises extruding the outer layer about thebraided assembly layer.
 19. The method according to claim 13 furthercomprising the step of forming at least one energy delivery elementabout a distal end of the outer layer.
 20. The method according to claim19 further comprising the step of electrically coupling at least one ofthe braid members to the at least one energy delivery element.
 21. Acatheter comprising: an elongate catheter body having an outer surface,a proximal portion, a distal portion, and an inner lumen extendingbetween the proximal and distal portions; a transducer disposed alongthe distal portion of the elongate catheter body; and a plurality ofelectrically conductive elements extending from the proximal portion tothe distal portion, wherein each of the electrically conductive elementshas a flexible dual-laminate coating comprising an inner layer and anouter layer, wherein the outer layer of the flexible dual-laminatecoating has a durometer of Shore D of about 40-50, and wherein theplurality of electrically conductive elements are in the shape of ahelical winding, and wherein the transducer is electrically coupled toat least one of the plurality of electrically conductive elements. 22.The catheter according to claim 21, wherein the electrically conductiveelements comprise a copper alloy or plated copper.
 23. The catheteraccording to claim 21, wherein a plurality of transducers are disposedalong the distal portion of the elongate catheter body.
 24. The catheteraccording to claim 21, wherein the catheter further comprises a heatshrink layer surrounding the outer surface of the catheter body.
 25. Thecatheter according to claim 21, wherein the transducer comprises anultrasound transducer.
 26. The catheter according to claim 21, whereinthe transducer is electrically coupled to a plurality of electricallyconductive elements.